\[\boxed{\text{5.\ 60}}\]
\[\textbf{а)} - 8x + 6x - 4x + 3x = - 3x\]
\[\textbf{б)}\ 4a - 7a + 3a - 10a = - 10a\]
\[\textbf{в)}\ 17c + 3c + 10c - 5c = 25c\]
\[\textbf{г)} - 4,5x - x + 4,5x + x = 0\]
\[\textbf{д)}\ 5n + 7,3n - 7,7n - 5n =\]
\[= - 0,4n\]
\[\textbf{е)} - 21c - 9c + 8,4c + 5,4c =\]
\[= - 30c + 13,8c = - 16,2c\]
\[\textbf{ж)}\ \frac{3}{7}m + \frac{3}{7}m - \frac{2}{7}m - \frac{6}{7}m =\]
\[= \frac{6}{7}m - \frac{2}{7}m - \frac{6}{7}m = - \frac{2}{7}m\]
\[\textbf{з)}\ \frac{1}{3}z - \frac{5}{6}z + \frac{1}{2}z - \frac{5}{12}z =\]
\[= \frac{4}{12}z - \frac{10}{12}z + \frac{6}{12}z - \frac{5}{12}z =\]
\[= - \frac{5}{12}z\]
\[\textbf{и)}\ y + 0,6y - \frac{2}{5}y - \frac{1}{4}y =\]
\[= 1,6y - 0,4y - 0,25y =\]
\[= 1,2y - 0,25y = 0,95y\]
\[к)\ 0,6c - 0,73c - \frac{3}{5}c + \frac{3}{4}c =\]
\[= 0,6c - 0,73c - 0,6c + 0,75c =\]
\[= 0,02c\]